FIGURE 1.

Col4a3bp expression in differentiating C2C12 myoblasts. A, C2C12 cells were serum-deprived, and at the indicated days, 50 μg of cell lysates were subjected to Western blot analysis with antibodies targeting MyoHC (Myosin), GPBP-1 and -2 (mAb 14), GPBP-1 and -3 (mAb e26), and tubulin. The bracketed arrows and arrowheads denote the position of GPBP polypeptides of the indicated molecular mass. B, the protein expression of mGPBP-1 in C2C12 differentiation assays (n = 2) was assessed by Western blot and quantified by densitometry with respect to tubulin expression. C, the RNA extracted from the cells in A was used for quantitative RT-PCR to determine the relative expression of the indicated mRNAs (bars). B and C, values are in -fold expression with respect to undifferentiated cells (day 0), which was set at 1. D, 3-day differentiated C2C12 cells were subjected to subcellular fractionation, and 15 μg of each of the indicated fractions were analyzed by Western blot for specific mGPBP-1 detection with mAb e26. Error bars, S.D.